DESCRIPTION (from applicant's abstract): This research examines reduction of medial consonant clusters within words and across word boundaries in normal and delayed phonological acquisition. Although there have been a number of studies of cluster reduction to date, very little is known about medial cluster reduction. Results of existing studies on word-initial and word-final cluster reduction in typically and atypically developing children show that cluster reductions are influenced by the relative sonority of the two consonants in the cluster. If the cluster occurs in word-initial/syllable-initial position, then the more sonorous consonant of the cluster is omitted. If the cluster occurs in word-initial/syllable-final position, then the least sonorous consonant of the cluster is omitted. Thus, children's cluster reductions are dependent on both the sonority of the consonants in the cluster and the position of the cluster in the word. In medial clusters, the position of the cluster is not as obvious as within monosyllabic words because of the influence of factors other than sonority on syllabification. The proposed studies investigate the influence of children's preferred syllable structure, word stress, and type of cluster (all factors that affect syllabification of medial consonant sequences), in addition to sonority, on cluster reductions in these positions. Furthermore, reductions of medial clusters formed across word boundaries (as in connected speech) as well as reductions of medial clusters within words will be compared and contrasted in typically developing children and in children with phonological disorders.